English: Schematic showing in which period there is a risk of conception (fertile period) and in which period there is no risk (safe period to engage in sexual intercourse). The schematic was made based on the schematic from Fertile Focus, and based on the safe period mentioned at the Understanding the female body article (namely 5 days before and 1 day after ovulation). Note that the exact time of ovulation varies between day 13 to day 15 -most ovulating at day 14 though-. As such, the fertile/unsafe period was extended to 8 days in the schematic.
increased unsafe (fertile) period due to uncertainty of exact time of ovulation (varies from day 13 to day 15, see http://www.fertilityfriend.com/Faqs/Ovulation.html )